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h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=gHKR1jOjt7QCu91OrQyhYTWE6z7tWRrsPrLcLJyogfZsmcrO1zcQzkTE/7l9qsV/i 09u12atqLLnIDhbZB5aAaH9CLlmnqRDuMy/SIGeu9zjyjxTgVGe3az0ZXn+5a/4q+y xwb5Dwiz9ZCSwCFmEtmfTNwzWAS01dpf47wxh5Tc= Message-ID: <42300e6c-523b-4f58-98f7-672ce9173fe2@arm.com> Date: Fri, 10 Jul 2026 18:43:14 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 5/5] mm/rmap: add anon folio unmap dispatcher To: "David Hildenbrand (Arm)" , akpm@linux-foundation.org, ljs@kernel.org, muchun.song@linux.dev, osalvador@suse.de Cc: riel@surriel.com, liam@infradead.org, vbabka@kernel.org, harry@kernel.org, jannh@google.com, lance.yang@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260710055915.638659-1-dev.jain@arm.com> <20260710055915.638659-6-dev.jain@arm.com> <00467fbf-0360-47be-94bc-d1456323e5a1@kernel.org> From: Dev Jain Content-Language: en-US In-Reply-To: <00467fbf-0360-47be-94bc-d1456323e5a1@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 1E57B20010 X-Stat-Signature: 4h7q48yw94ft34wcz5y45gnwy4e1u59w X-HE-Tag: 1783689201-344588 X-HE-Meta: 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 wJAiqhah e8zYJ3X7aUMy6I/Yloc+HuNNDBsJZlenQontquGuoCDTftKzV18V0jAjSrzC8W8AIt687yAmrM+wSlj6qCqLBz1rOfPITAduM90gWuMFa7MBb63WRUIej/s/6HEG5ySlZB8Bii/z2jeyudxTuvDUdmQkEboB2EG122cwAAvdY2uJwu6miG7Bpfj969xONSVT3hTiM15wPZETu/efGbNUy32pjww2bKPvffpgYYYXdLHO5KTUd62vUPs7gEX+SC+25kDe4eP2BGxh90crkR28WVsvC/GB2YlNsTIW8Mn5bQKGJFGxDm+MrnQl4vmAGJyEsbZbp Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 10/07/26 5:57 pm, David Hildenbrand (Arm) wrote: > On 7/10/26 07:59, Dev Jain wrote: >> Add ttu_anon_folio() as the common entry point for anonymous folio >> unmapping. It dispatches to the lazyfree or swapbacked helper as >> appropriate. >> >> Keep restoration of cleared PTEs in the caller, where the PTEs were >> removed. >> >> No functional change intended. >> >> Signed-off-by: Dev Jain >> --- >> mm/rmap.c | 47 +++++++++++++++++++++++++---------------------- >> 1 file changed, 25 insertions(+), 22 deletions(-) >> >> diff --git a/mm/rmap.c b/mm/rmap.c >> index 68459f23f5c0a..55aa3ff8bf216 100644 >> --- a/mm/rmap.c >> +++ b/mm/rmap.c >> @@ -2172,6 +2172,28 @@ static bool ttu_anon_swapbacked_folio(struct vm_area_struct *vma, >> return true; >> } >> >> +static bool ttu_anon_folio(struct vm_area_struct *vma, struct folio *folio, >> + struct page *page, unsigned long address, pte_t *ptep, >> + pte_t pteval, unsigned long nr_pages) >> +{ >> + /* >> + * Store the swap location in the pte. >> + * See handle_pte_fault() ... >> + */ >> + if (unlikely(folio_test_swapbacked(folio) != >> + folio_test_swapcache(folio))) { >> + WARN_ON_ONCE(1); > > Can't you directly do > > if (WARN_ON_ONCE(...)) > return false; Right. I didn't do it perhaps because I was playing with if (VM_WARN_ON_ONCE) somewhere and that didn't build. But this is without the VM_ , this will work. Andrew, could you you squash this diff: diff --git a/mm/rmap.c b/mm/rmap.c index 55aa3ff8bf216..41a049e7dd231 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -2180,11 +2180,9 @@ static bool ttu_anon_folio(struct vm_area_struct *vma, struct folio *folio, * Store the swap location in the pte. * See handle_pte_fault() ... */ - if (unlikely(folio_test_swapbacked(folio) != - folio_test_swapcache(folio))) { - WARN_ON_ONCE(1); + if (WARN_ON_ONCE(folio_test_swapbacked(folio) != + folio_test_swapcache(folio))) return false; - } if (!folio_test_swapbacked(folio)) return ttu_anon_lazyfree_folio(vma, folio, nr_pages); > > That even implies the unlikely() :) > >> + return false; >> + } >> + >> + if (!folio_test_swapbacked(folio)) >> + return ttu_anon_lazyfree_folio(vma, folio, nr_pages); >> + >> + /* nr_pages > 1 not supported yet */ >> + return ttu_anon_swapbacked_folio(vma, folio, page, address, ptep, > > LGTM > > Acked-by: David Hildenbrand (Arm) >